1. Field of the Invention
Disclosed is an automated apparatus for spray wetting a glue covered region on an envelope flap and sealing the wetted envelope flap to an associated envelope. More specifically, a dynamically controlled wetting and sealing system having a spraying module, a sealing unit, and control means is related.
2. Description of the Background Art
Various examples of envelope processing equipment include relatively rudimentary means for sealing the envelopes that are processed. Often a type of wet sponge or wet brush is contacted with a flap gluing strip on the envelope.
Specifically, commonly assigned and divisional U.S. Pat. Nos. 4,798,040 and 4,922,689 disclose an insertion machine containing an envelope sealing station. The sealing station comprises a pair of sprayers with each having a liquid line and an electrical line. An envelope presence detector signals to activate the sprayers to wet an incoming envelope as it passes.
U.S. Pat. No. 3,911,862 relates an envelope flap moistening apparatus. Comprising the device is a set of spray nozzles that are adjustable via associated solenoids that alter the vertical positions of the nozzles. Envelope and flap detection means are included and comprise light emitting diodes and photoelectric detectors.
Provided in U.S. Pat. No. 2,114,814 is a stuffing and sealing machine. A bottle supplies water to wet the envelope glue strip. A throw member serves to press the wetted flap against the envelope for sealing.
A device for transforming envelopes and the like is presented in U.S. Pat. No. 3,550,351. Brushes wick fluid from a water tray and apply it to the envelope flap. Rollers seal the wetted envelope.
U.S. Pat. No. 4,205,504 describes a method and device for making envelopes from a continuous web and includes the stuffing and sealing of those envelopes. Specifically, glue strips are provided in appropriate locations to adhere to one another during the assembly process.
An envelope mailer is supplied in U.S. Pat. No. 5,005,337. A gluing station is present that applies glue via rollers. Sealing is by a series of subsequent rollers.
U.S. Pat. No. 5,042,223 discloses an article positioning control apparatus including an envelope flap moistening station having a water tank.
The usefulness of the prior art wetting-sealing devices is limited by such practical considerations as awkward multiple spray nozzles, efficient or effective wetting that occurs only when the envelopes travel at a set velocity, wetting means that require time to recover activity when the passing envelopes are halted, wetting and sealing envelopes for which an error has occurred in which the erred envelope should not be wetted and sealed, and the requirement of an envelope location sensor to determine if an envelope is ready to be wetted. By means of an overseeing computer controller and strategically designed wetting and sealing means, the subject system provides an integrated sealing scheme that dynamically merges a spray wetting module with a sealing unit to overcome the limitations presented in the existing wetting-sealing devices. Further, since the subject system utilizes a shaft encoder coupled to the associated inserter machine and a controller that tracks when envelopes enter the inserter, no envelope location sensor is required in the subject invention, unlike the existing devices currently employed in the industry.